1. Field of the Invention
The present invention relates to a semiconductor laser device.
2. Background Art
Various types of semiconductor laser devices are conventionally known, including those for DVD writing or information processing, solid state lasers such as Nd-doped YAG (Nd:YAG) lasers and Yb-doped YAG (Yb:YAG) layers, pumping source lasers such as Yb-doped fiber lasers and Er-doped fiber amplifiers, and lasers for optical communications. J. Sebastian et al. disclose a semiconductor laser device including a structure in which a GaAsP active layer is sandwiched between AlxGa1-xAs optical guiding layers having the same thickness and composition. (See J. Sebastian et al., “High-Power 810-nm GaAsP-AlGaAs Diode Lasers With Narrow Beam Divergence,” IEEE J. Select. Topics In Quantum Electron., vol. 7, No. 2, pp. 334-339, 2001.) This structure allows the semiconductor laser device to operate at high output power. Other prior art includes Japanese Laid Open Patent Publication Nos. 11-233882 (1999), 11-233883 (1999), 11-243259 (1999), 2006-32437, and 11-163458 (1999).